From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [git patches] libata fixes Date: Wed, 27 Jun 2007 03:47:31 -0400 Message-ID: <46821613.9010305@garzik.org> References: <20070627073526.GA18787@havoc.gtf.org> <20070627003841.68fd0ea9.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:38408 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752335AbXF0Hrd (ORCPT ); Wed, 27 Jun 2007 03:47:33 -0400 In-Reply-To: <20070627003841.68fd0ea9.akpm@linux-foundation.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Andrew Morton Cc: Linus Torvalds , linux-ide@vger.kernel.org, LKML Andrew Morton wrote: > On Wed, 27 Jun 2007 03:35:26 -0400 Jeff Garzik wrote: > >> + /* Don't allow DMA if it isn't multiple of 16 bytes. Quite a >> + * few ATAPI devices choke on such DMA requests. >> + */ >> + if (unlikely(qc->nbytes & 15)) >> + return 1; > > It might be worth emitting a diagnostic when this happens. I tend to disagree, but if any screaming users show up, we can certainly think about adding some. Such would be a diagnostic that would trigger on valid SCSI commands, when the user is doing nothing wrong and the system can indeed complete the command just fine. Additionally, this is moving us in the direction of what the IDE driver has apparently been doing. Jeff